FIELD: insulating materials.
SUBSTANCE: invention is related to an additive for use in a method for producing an insulation system using the VPI technology, a vacuum pressure impregnation method in which a solid insulating material is impregnated with an impregnating resin containing epoxy groups at elevated temperature and under reduced pressure. A composition for a VPI process is proposed, comprising a solid insulating material and an impregnating composition based on a resin containing epoxy groups for obtaining an anhydride-free insulation system with VPI, which contains an additive for better distribution of an anhydride-free curing catalyst, and the additive includes one or more phenyl esters carboxylic acids and is present, based on the epoxy groups of the epoxy-rich resin contained in the impregnation composition, in an equivalent stoichiometric amount of at least 0.1%, wherein the additive comprises at least one carboxylic acid phenyl ester of the formula selected from the group consisting of 7 compounds.
EFFECT: additive for an epoxy-containing impregnating composition, phenyl carboxylic acid esters, disclosed for the first time, allow sufficient reactivity even in anhydride-free impregnating compositions when used in the VPI process for impregnating solid insulating materials with the introduction of curing catalysts in areas with a low concentration of curing catalyst for curing to thermoset polymer and thereby to form a moulded material.
12 cl, 6 dwg
